Drill



Oct, 14 119240 A. L. HAWKESWORTH DRILL 2 Sheets-She et 1 Filed July '7, 1922 Get. 14 M3 24e A. L. HAWKESWORTH DRILL Filed July '2 1922 2 Sheets-Sheet 2 Patented a. 14, 1924.

UNITED STATES'PATENT OFFICE.

ARTHUR L. HAWKESWOBTH, OI BUTTE, HOINTANA, ASSIGNOB TO KAWIESWOB'IE DRILL COMPANY, OF BUTTE, MONTANA, A CORPORATION 01' DELAWARE- DELHI:-

Application filed lluly 7, 1922. Serial No. 573,888.

To all whom it may concern:

Be it known that I, An'rnun L. HAWKES- won-r3, a citizen of the United States, residing at Butte, in the county of Silverbow and State of Montana, have invented certain new and useful Im rovements in Drills, of which the following 1s'a specification.

My invention has relation to improvements in drills having detachable bits which may be quickly and readily detached when occasion arises therefor, for example, where a bit must be removed for sharpening and a new hit substituted, or when it is desired to take the bit oif for safe-keeping, or for any other purpose. A further object of the invention is to provide a passage-way in the shank for the flow of water or air, said passage-way communicating with a duct between the shank and bit for the lateral discharge of the water or air into the hole. A further object is to provide a drill having communicating ports in hit and shank for the flow of cleaning fluid therethrough, with auxiliary outlet ports in the shank. A fur- 2 ther object is to provide a drill having a detachable bit terminating in a plurality of cutting edges, some of which are notched to relieve the bit of cutting surface where not required. Further objects will be better apparent froma detailed description of the invention in connection with the accompanying drawings, in which- Figure 1 represents an elevation of my improved drill turned so as to present the narrow ends of the central or main inter locln'ng groove and tongue of the shank and bit respectively; Fig. 2 is a side elevation of the drill; Fig. 3 is an elevation of the bit detached from the shank and turned to resent the narrow end of its central tongue; ig.

4 is an elevation ofthe shank turned to present the narrow end of its central groove receiving the corresponding tongue of the bit, and the wide ends of the tongues bounding said groove which enter corresponding grooves of the bit; Fig. 5 is an elevation of the drill turned at an angle of 45 from Fig. 1 so as to present the sides of the notched cutting legs; Fig. 6 is an elevation of the bit detached from the shank and turned at an angle of 90 from Fig. 5 so as to present the sides of the cutting legs that are not notched but extend from side to side of the bit; Fig. 7 is a plan of the cutting surface of'the bit; Fig. 8 is a plan of a bit cutting surface showing three of the cutting legs notched instead of two; Fig. 9 is an elevation of a form of drill showing a groove for the passage of water or air in the bit tongue instead of in the shank as shown in Fig. 1; Figures 10 and 11 are views of the drill shown in Fig. 9 with the bitand shank detached similar to Figures 3 and 4 of the main form; Fig. 12 is a modified form of drill similar in all respects to the main form (Fig. 2) except that the inclined ports for lateral discharge of water discharge below the ends of shank groove instead of at each side beyond said groove; Fig. 13 is a further modification showing central tongue and groove with vertical sides instead of dovetailed.

Referring to the drawings, and for the present to Figures 1 to 7 inclusive, 1 represents a drill-bar or shank and 2 the bit adapted to be passed across the axis thereof, said shank and bit having cooperative for mations whereby they are effectively interlocked against relative displacement, the bit, at the same time, being readily detachable from the shank. These interlocking formations are the same as those shown in my Letters Patent'No. 1,328,325, dated January 20, 1920, and consist in a dovetail groove 3 in the'shank bounded by dovetail tongues 4, 4 which cooperate with a dovetail tongue 5 on the bit bounded by dovetail rooves 6, 6, all of said formations being inc ined to the axis of the drill. The side walls of the tongues 4, 4 taper in the eneral direction toward the cutting end 0 the drill while the side walls of groove 3 taper in the opposite direction so that on inserting the narrow end of tongue 5 into the wide end of groove 3, the narrow ends of tongues 4, 4 9 of the shank will at the same time be received by the wide ends of grooves 6, 6 of the bit, and as the bit is moved across the shank, the respective formations will interlock until further movement of the bit is 1 arrested, when the axis of shank and bit are in alinement. This arrest is effected by the wedging action between tongue 5 and groove 3 on the one hand, and the tongues 4, 4 and grooves 6, 6, on the other hand, the reverse 1 tapers of the respective tongues and their cooperating grooves operating to efi'ect a positive locking of the bit to the shank. Obviously, the blows to which the drill is subjected in drilling operations will tend 1 0 i to tighten the bit on the shank, said bit besubstantiallyl ing readily removed, however, by a slight blow with a hammer against. the bit on the same side with the narrow end of tongue 5.

In the present case the bit is provided with o positely disposed cutting legs 7, 7 and 7 7', the legs 7, 7 terminating in beveled faces a, 0. extending continuously from one 1e to the other to em a cutting ed e e, whi e the legs 7", 7 have inwardly inc ed faces 0, 0 cut in them, said faces intersecting bevel faceslb, b, b, b, of said legs 7', 7' and removing the inner part of each cuttin edge. e, e. Thus the cutting legs 7', 7 have cutting edges only on the outer art toward their peripheral edges,

while egs 7 7 have cutting edges extending from the center of bit to the periphery t ereof. The object of thus decreasing the cutting edge at the center of the bit is twofold. In the first place, less material has to be removed from the center of a drilled hole than from the greater outer area, and in the second place, to produce the inclined faces 0., o the cutting surface of the bit is provided with the notches n, n which relieve the resistance on the bit, facilitate the washing out of the cuttings, and result in faster cutting by the bit. v

The shank 1 is provided with an'axially disposed port or passage-way (1 having an out et communicating with a groove 9 connected to" groove 3 and forming the bottom thereof, and the bit 2 is provided with a port d in alinement with port d.. The shank 1 is further provided with two inclined ports h, h branchmg off from port (1 and each havindg an outlet just under the bit 2 between a Jacent cutting legs. In the-drilling operation water .(or air) is caused to flow through port (2, some of said water discharging through roove 9, some through port 11' and some t rough ports h, h, and

washing the cuttings away from the cutting surface of the bit. .If the port d only were provided for the discharge of the water (as as heretofore been the case) the drill would have tobe withdrawn in case this port'became stopped up. In the present case not only will the drill operate satisfactorily when port d is stopped up, but this port maly even be dis ense with entirely.

n Fig. 8 I s ow a plan of the cutting face of another form of bit wherein three 0 the legs 7', 7 7 are provided with notches ndleaving but one leg 7 having a cutting e rip eral edge.

. to side thereof.

0 extending from the center to the pe-'- "nausea Figures 9, 10 and 11 show another form of the drill differing from the main form in that instead of groove i being rovidedin the shank, a groove 9' is forme in the botthat inclined ports h, h are disposed at an angle of 90 from their position in Fig. 2,. discharging beneath the ends of tongue 5.

In Fig. 13 the interlocking formations of shank, and bit are modified somewhat, the ten e 10 of bit 2 and its cooperating groove 11 aving per endicular sides instead of blein dovetaile and tongues 12, 12 of the s a in the bitalsohaving perpendicular sides, the groove and cooperating tongue gradually widenin toward the cutting end of the bit as in t e main form.

1' and its cooperating grooves 13, 13

Obviously,-it is within the spirit of 'my invention to construct the cooperative formations of bit and shank of the main form in the manner just described, or. combine the various modlfications illustrated in any manner most desirable to suit iven conditlons, since all of the novel eatures described are capable of being combined in one form of drill.

Having described by invention, I claim;

1. In combination with a drill-bar or shank, a .bit detachably soured thereto, said shank having an axially disposed passa e-. way extending therethrough, and one of t e" 1 bit-engaging transverse surfaces of the shank having a groove extending from side 2. In combination "with a drill-bar or shank, a bit movable across the axisof the" 1 shank, a transverse dovetail ton e tapering in a'glven directlon and boun mg. grooves tapering in the opposite direction formed on one. of the members, acorrespondingdovetail tapering groove and bounding tongues on the opposite member interlocking with the formations on the first member, the

transverse engaging surfaces between the members being mclined to the axis of the shank, said shank being provided with'an v axial port extending therethrough, said port with a longitudinally dis posed groove ormed in the tongue of the bit.

communicatin In testimony whereof I hereunto afiix my signature.

ARTHUR L. HAwK sWoR'rH 

